If your going Intel go for a z77 board..
If the budget is really tight then drop in an i3 which you can then drop in an i5 or i7 when you have the funds (possibly second hand to save more) point being the board will take a bigger chip and oc when you have the extra to do so.

If you grab an i3, spend the rest on your GPU. AMD tend to give better bang for your buck.

AMD CPU may be better for your needs though. Cheaper for more cores.
Not as good at single or lightly threaded stuff (games, general desktop stuff and it's not bad, just not as good) but possibly better for video editing (check your software for what it uses / supports)